Found the helium pressure had been turned down to about 6 Torr instead of the maximum of 9.9 T. When I adjusted the He pressure to the correct setting, the helium flow increased to 5.0. This indicates a huge helium cooling leak. When I opened the chamber, I found wafer chips underneath the wafer lifter. This caused the lifter to sit slightly above the surface of the electrode.
Helium readings now are back to normal.
2.3 : With the wafer loaded and before the process starts
3.7 - 4.0 : During process (no wafer holder)
Nancy will run another test tomorrow